1. Field of the Invention
This application relates in general to apparatus for producing ozone for the elimination of chemical odor, germs, and other organic particulate matter in an enclosed space, and more particularly to ozone generating apparatus using sensors which allow the personal safety, efficient purification, and damage prevention associated with well known adverse effects of ozone overexposure in an enclosure.
2. Description of the Prior Art
Ozone generating apparatus has a long history in the prior art. The present application focuses on a portable ozone generating device such as that disclosed in U.S. Pat. No. 4,863,701 issued to the present inventor on Sep. 5, 1989. In that device, ozone was generated by electrostatic discharge using an array of glass tubes each containing a conductive rod serving as a core. Adjacent tubes were parallel to each other and the conductive rod of each tube is connected to the secondary terminal of a high voltage transformer. The tubes containing the conductive rods serve as an electrode when the voltage transformer is activated thereby creating an electrostatic field. Oxygen molecules in the electrostatic field are transformed to form ozone molecules. This prior art apparatus can be applied to deodorizing an enclosed space with the addition of a fan to feed oxygen past the tube array and distribute the ozone that is generated. After the ozone generation cycle stops, and to reduce excess ozone concentration in the enclosure, the apparatus had an odor emitting chamber which opened allowing a substance of choice causing breakdown of ozone molecules present. In this apparatus the ozone decomposing substance, intended to be a pleasant scent such as any one of the a number of perfumed scents, was released at the end of the ozone generating cycle in the same amount regardless of the amount of ozone present. A major drawback would occur if the ozone concentration in the enclosure after deodorizing was high enough to break down the perfumed scent and remain at a high level. Monitoring of the ozone level in the enclosure or the level of perfumed scent did not occur, nor was control of the ozone generating cycle relative to the release of the ozone decomposing vapor present.
A search of the prior art has revealed several patents with the last decade which attempt to monitor the ozone generating cycle.
______________________________________ U.S. Pat. No. Inventor Issue Date ______________________________________ 5,368,816 Detzer 11/26/94 5,266,275 Faddis 11/30/93 5,256,377 Nakamaru, et al 10/26/93 4,842,829 Hirai, et al 6/27/89 4,853,735 Kodama, et al 8/1/89 ______________________________________
Generally, these patents differ from the present invention which provides an air and surface antiseptic purifying system using ozone and electronic logic circuitry used to monitor operating cycles according to feedback from sensors. Apparatus used to purify enclosures has strict safety considerations as ozone in suitable germicidal concentration can be harmful to human or animal life. (See 21 CFR 801.415) It is imperative that ozone generating apparatus to be successfully employed have safeguards built-in to the apparatus which assure its fail safe operation. Each of the above patent has a safe use of ozone generating apparatus as a goal but the individual embodiments differ from applicant. For example, in U.S. Pat. No. 5,368,816 issued to Detzer, ozone is added to a stream of air circulating through an air conditioning system to oxidize pollutants. A filter downstream of the ozone generating device is used to decompose any ozone after this operation. Sensors further downstream detect if the ozone concentration of the conditioned are as below a minimum safety level. Applicant's device, in contrast, does not require a filter, nor a sensor which detects ozone over a preset level resulting in a shut down of the entire system. The other patents in the search differ in structural and/or functional features relative to the present application and are cited of interest in a general nature. The teachings of these patents alone or in combination, would not anticipate or render obvious applicant's invention as later claimed in this application.
A major problem in ozone application in an enclosure continues to be possible damage due to ozone concentrations over a period of time. Ozone is known to cause premature aging of rubber items, plant foliage and other material affected by oxidation. A device set to run 12 hours in an enclosure may take only two hours to purify that environment with ozone, or may take twelve hours depending on the pollutants and odor present in the enclosure. It is desired to find an apparatus which will produce only enough ozone required to purify the environment without exposing the susceptible contents of the enclosure to ozone degradation. The present invention seeks to solve this problem.
With respect to indicators of hazardous unseen materials, the prior art contains devices which, for example, change color when exposed to various chemicals. Also electronic monitors which are relatively expensive are known. These indicators may require matching a color which can be problematic for those who have difficulty discerning colors or the very young. The present invention overcomes these difficulties and provides a simple and easily readable device.